Desiccant dehumidifier utilizing hot water for reactivation, and related method

Abstract

An air conditioning system includes a refrigeration cooling coil in fluid communication with process air, a refrigeration circuit containing refrigerant, a heat exchanger in fluid communication with the refrigerant and water, the heat exchanger adapted to transfer heat from the refrigerant to the water, a hot water coil in fluid communication with the water, a desiccant rotor having a process portion in fluid communication with the process air and a reactivation portion, and a reactivation blower adapted to move reactivation air over the hot water coil and through the reactivation portion of the desiccant rotor. A method of conditioning air is also described.

1 . An air conditioning system, comprising:
 a refrigeration cooling coil in fluid communication with process air;   a refrigeration circuit containing refrigerant;   a heat exchanger in fluid communication with the refrigerant and water, the heat exchanger adapted to transfer heat from the refrigerant to the water;   a hot water coil in fluid communication with the water;   a desiccant rotor having a process portion in fluid communication with the process air, and a reactivation portion; and   a reactivation blower adapted to move reactivation air over the hot water coil and through the reactivation portion of the desiccant rotor.   
     
     
         2 . The air conditioning system of  claim 1 , further comprising:
 a process air blower adapted to move the process air over the refrigeration cooling coil and through the process portion of the desiccant rotor.   
     
     
         3 . The air conditioning system of  claim 1 , further comprising:
 a refrigerant compressor in fluid communication with the refrigeration circuit.   
     
     
         4 . The air conditioning system of  claim 3 , wherein the refrigerant compressor comprises a speed-controlled compressor. 
     
     
         5 . The air conditioning system of  claim 3 , further comprising:
 a second refrigerant compressor in fluid communication with a second refrigeration circuit; and   a second heat exchanger in fluid communication with the second refrigerant circuit and the water.   
     
     
         6 . The air conditioning system of  claim 5 , wherein the first refrigerant compressor and the second refrigerant compressor are fixed-speed compressors. 
     
     
         7 . The air conditioning system of  claim 5 , further comprising:
 a second refrigerant cooling coil in fluid communication with ambient air, the second refrigerant system in fluid communication with a heat exchanger;   wherein the heat exchanger is in fluid communication with the water, and the refrigerant system absorbs heat from the ambient air to heat the water.   
     
     
         8 . The air conditioning system of  claim 1 , further comprising a second hot water coil in fluid communication with ambient air and in fluid communication with the hot water. 
     
     
         9 . The air conditioning system of  claim 1 , further comprising:
 a secondary fluid heat exchanger in fluid communication with the hot water and in fluid communication with an external fluid to be heated;   wherein excess heat is rejected into the external fluid to be heated through the secondary fluid heat exchanger.   
     
     
         10 . A method of conditioning air, comprising:
 circulating refrigerant through a cooling coil;   moving process air over the cooling coil;   moving the process air through a process portion of a desiccant wheel;   exchanging waste heat from the refrigerant to a flow of water;   heating a hot water coil with the flow of water; and   moving reactivation air over the hot water coil and through a reactivation portion of the desiccant wheel.   
     
     
         11 . The method of  claim 10 , further comprising:
 moving the process air into a room or process space.   
     
     
         12 . The method of  claim 10 , further comprising:
 moving ambient air over an evaporator coil to extract heat from the ambient air to the refrigerant; and   transferring the heat from the refrigerant to the flow of water and to the hot water coil.   
     
     
         13 . The method of  claim 11 , wherein the heat is transferred from the flow of water to the hot water coil through a heat exchanger. 
     
     
         14 . The method of  claim 10 , further comprising:
 directing the flow of water through a heat exchanger;   exchanging heat from the flow of water to a fluid; and   using the heated fluid in an external process.